I have a Samsung syncmaster 2443NW monitor - currently I'm borrowing a LG Flatron w2246 (although this is in no way a long-term solution). I used the monitor's manual to check the monitor - apparently it is working fine and the problem is with my computer. However, my computer is working fine with a different monitor. Only a couple of days ago my monitor was working perfectly fine until I changed a couple of components in my computer.
I upgraded my Radeon HD 4850 to a Radeon HD 7850. Now when I use my Samsung monitor it appears to be in power save mode (the monitor light flashes suggest this). Following directions from the monitor manual, I can briefly take the monitor out of powersave a couple of time. Similarly when I log in to Windows 8 the screen displays for a few seconds. Even when it displays, though, the display is in a low resolution, off=centre, and very red. I have used the LG monitor to install the new GPU drivers and adjust the resolution.
If it helps I am using the DVI to VGA adaptor which came with the graphics card to connect the monitor in (it only has a VGA connection). Also, I have had this problem before, although it was sorted last time (can't remember how, but think it was by updating the graphics drivers).
As far as I am aware, everything is working perfectly - except that my normal monitor won't display properly with my PC.